What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCBoth

LOINC Code 639-5: Microscopic observation KOH prep Nom (CSF)

Name: LOINC Code 639-5: Microscopic observation KOH prep Nom (CSF)
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:43.947Z

639-5 is a LOINC code used to identify Microscopic observation KOH prep Nom (CSF) in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Observation. It is commonly used with the system or sample type CSF.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Observation. It is commonly used with the system or sample type CSF.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: DISCOURAGED
Order vs observation: Both
Method: KOH preparation

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

Microscopic observation [Identifier] in Cerebral spinal fluid by KOH preparation

Observation

A KOH Preparation involves treating a specimen with KOH, a strong base that can make fungi and yeast more visible by partial dissolution of tissue cells, keratin, and other material. Fungal cells are resistant due to the high content of cellular chitin. KOH prep is generally a test for fungi, most often candida yeast, but others too, such as tinea capitis and other skin or nail fungal infections, even blastomycosis, etc. However, the KOH prep is also used to diagnose infections with mites (Demodex folliculorum in rosacea-like lesions and Sarcoptes scabiei in hyperkeratotic or crusted scabies) and sometimes even nematodes (in blue neck syndrome). [PMID16766846]

Cerebral spinal fluid; Cerebrospinal Fl; ID; Identity or presence; Infectious Disease; InfectiousDisease; Microbiology; Neuro; Neurology; Nominal; Point in time; Potassium hydroxide preparation; Prep; Random; Spinal Fl; Spinal Fld; Spinal Flu; Spinal Fluid

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Microscopic observation KOH prep Nom (CSF)Microscopic observation [Identifier] in Cerebral spinal fluid by KOH preparationKOH Prep CSFObservationMICROSpinal fluid KOH testPrid

Frequently asked questions

Code details

Code639-5

SystemLOINC

Display nameMicroscopic observation KOH prep Nom (CSF)

DescriptionObservation

Short nameKOH Prep CSF

ComponentObservation

PropertyPrid

TimingPt

System (specimen)CSF

ScaleNom

MethodKOH preparation

ClassMICRO

StatusDISCOURAGED

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0

Last changed2.78

Consumer names

Spinal fluid KOH test

Part names

ObservationPridPtCSFNomKOH preparationPresence or IdentityPoint in time (spot)Cerebral spinal fluid

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.